From 7f21aeef722d598ba350d1834f6e4134c7b5e8de Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 15 Aug 2015 14:49:50 -0700 Subject: [PATCH] rcu: Add online/offline info to stall warning message This commit makes the RCU CPU stall warning message print online/offline indications immediately after a hyphen following the CPU number. A "O" indicates that the global CPU-hotplug system believes that the CPU is online, a "o" that RCU perceived the CPU to be online at the beginning of the current expedited grace period, and an "N" that RCU currently believes that it will perceive the CPU as being online at the beginning of the next expedited grace period, with "." otherwise for all three indications. So for CPU 10, you would normally see "10-OoN:" indicating that everything believes that the CPU is online. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 06116ae6dfd7..57ed9c13ae5a 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1702,8 +1702,12 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu) ticks_value = rsp->gpnum - rdp->gpnum; } print_cpu_stall_fast_no_hz(fast_no_hz, cpu); - pr_err("\t%d: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n", - cpu, ticks_value, ticks_title, + pr_err("\t%d-%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n", + cpu, + "O."[!!cpu_online(cpu)], + "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)], + "N."[!!(rdp->grpmask & rdp->mynode->qsmaskinitnext)], + ticks_value, ticks_title, atomic_read(&rdtp->dynticks) & 0xfff, rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting, rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu),